Influence of human tooth cryopreservation on dentin bond strength.
OBJECTIVE
The goal of this study was to evaluate the effects of cryopreservation of teeth on dentin bond strength as a function of remaining dentin thickness.


METHODS
Flat occlusal surfaces of human dentin were prepared in 54 freshly extracted teeth and 54 thawed, cryopreserved teeth. In each group, 18 bonds were performed in superficial dentin, 18 in mid-coronal, and 18 in deep dentin. A resin composite cylinder, 3 mm in diameter and in height, was bonded orthogonally to the surface. After storage in distilled water at room temperature for 1 wk, the bonded cylinders underwent shear testing at a crosshead speed of 0.5 mm min-1. The mean remaining dentin thickness was calculated after longitudinally sectioning the debonded samples through the center of the bonded area. Non-parametric statistical analyses were used to correlate the shear bond strength with the remaining dentin thickness among the storage modes and within the different dentin regions.


RESULTS
The lowest shear bond strength values were found in the deep dentin of both fresh and cryopreserved dentin, while the values in deep and mid-coronal dentin were not significantly different in fresh and cryopreserved dentin. In the superficial and mid-coronal dentin of cryopreserved samples, the shear bond strength values were identical. There was a significant difference between the shear bond strength values in the superficial dentin of fresh teeth compared to the values for cryopreserved teeth.


CONCLUSIONS
According to the experimental conditions, tooth cryopreservation shows some promise as a substitute for freshly extracted teeth, provided that the experiments are performed in midcoronal and deep dentin.
Panighi
M M
MM
Faculté d'Odontologie, Université H. Poincaré, Nancy, France. panighi@ciril.fr
Allart
D
D
Jacquot
B M
BM
Camps
J
J
G'Sell
C
C
D003188:Composite Resins; D015925:Cryopreservation; D001840:Dental Bonding; D018865:Dental Research / Q000379:methods; D003804:Dentin / Q000737:chemistry*; D017220:Dentin-Bonding Agents; D005069:Evaluation Studies as Topic; D006801:Humans; D016014:Linear Models; D008422:Materials Testing / Q000379:methods; D019279:Resin Cements; D012822:Silicon Dioxide; D013048:Specimen Handling / Q000379:methods*; D018709:Statistics, Nonparametric; D013718:Tensile Strength; D015040:Zirconium
D003188:Composite Resins; D017220:Dentin-Bonding Agents; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C083568:Z100 composite resin; D012822:Silicon Dioxide; D015040:Zirconium